add public_labels to pio_kwargs

[Gebhartj]

No description provided.

[jepler]

I think that the correct place for this information is not in the "pio_kwargs", because a program which uses this feature would not be able to pass **program.pio_kwargs to the StateMachine constructor.

Instead, it should go in some other property of the Program object.

I would also like to see a test added. The test would assemble a PIO program that uses public labels, and then assert that the new public_labels property has the expected value.

Finally, there may be some feature in the circuitpython core that is needed to make this useful, since a PIO program can be loaded at an offset other than 0. Right now, I don't think there's a way to find the load offset from a StateMachine object. (incidentally this is the only reason that I added and then used ".offset" for some personal code: so that I could "jmp 0" under Python control...)

Thank you! Please feel free to give me a direct ping if I overlook your update of this PR.

[jepler]

I've added #72 as an alternative to this. It creates a new public_labels property on Program objects. Please let us know in a comment if this fits your use cases.

[jepler]

Thanks for offering this improvement! While we didn't ultimately merge your PR we implemented similar functionality in #72 so please check it out. You're encouraged to open further issues or PRs if your needs still aren't met.